Although this problem was posted a long time ago, apparently only one other person tried to help. So let me throw my two cents into this situation.
While you did defrag the hard drive, you did not mention whether you did an old fashioned disk check on it. In most Windows versions, if you open Windows Explorer (Window key+E) you will get a directory of your drives and folders. Find your "C" drive, right-click on it, and choose "properties."One of the tabs at the top of the box that opens should say "tools."
One of those tools will give you the option of checking and correcting the hard drive for errors, caused by numerous reasons. Especially if you haven't done this in years.
Place a check in each box in the options for checking and correcting, even though it says that it won't happen until you restart your computer.
So, close all other applications of every kind, then choose to shut down and restart your computer.
Be prepared for a long time to elapse while the computer finds and, if necessary, fixes bad spots on your hard drive. In most cases, Windows will relocate your data to a different location, so that you do not lose anything, if it happens to find a problem or more than one problem on your hard drive.
Just be patient and allow Windows to do its work, fixing your system.
When it is done, Windows will restart, and your system may actually be faster than before.
One thing you should be most aware of - if you don't have a lot of memory, even if Windows finds and fixes hard disk problems, it is not going to do miracles and make your computer run faster than ever before. It can only go as fast as the amount of memory you have will allow it to go. But if there have been disk problems, and they have now been fixed, then your computer should run faster than it has in the past, since it doesn't have to deal with bad spots on the hard disk. And those spots will be marked by the system so that they will not be used again, thus protecting you from putting data there and slowing your computer down once again.
Defrag your computer at least once a month, and treat it right. It should last a while for you and do the tasks you need done.
I do hope this helps you.